Normally I'd recommend increasing the co2 but noticed you have intolerant shrimp in the tank. Growth is triggered by light so cutting back the photo period or breaking up the period into two parts may help. Cutting back on phosphates when dosing might help a bit.
Seems like you don't have sufficient plant density to take advantage of the light intensity. Adding some fast growers or floaters would help your plants outcompete for nutrients with algae...
The Aquatic Plant Society Curator of the NY/NJ/CT LFS & CO2 Directory
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